A smoke detector or smoke alarm is usually mounted on the ceiling of a room or structure. The device will be programmed to sound off and alert occupants to the detection of excessive smoke. Smoke detectors can, however, signal a false positive; that is, sound off when there is no danger of fire. For example, some smoke detectors sound off when a harmless activity in the kitchen of a home or apartment produces a large amount of smoke. Although most smoke detectors can be silenced by complete disarming or deactivation, further developments could improve the ability to reduce false positives or silence smoke alarms when there is no danger of fire.